The present invention relates to apparatus for determining and storing, in a non-volatile, substantially permanent memory, certain statistical information. More particularly, the invention concerns apparatus for accumulating (counting) the occurrences of different types of events and storing these counts in substantially permanent form.
There are many situations in which the occurrences of events of different types are to be counted to create statistical data in the nature of a historical profile. For example, it would be desirable to record a "milage histogram" of a motor vehicle, such as an automobile. Although most motor vehicles have a mechanism (either mechanical or electronic) called an "odometer" for permanently recording the total number of miles that the vehicle has been driven, this data (total miles) is not very informative about the condition of the vehicle. Data concerning the length of the trips that the vehicle has been driven would be also very valuable in evaluating the condition of the vehicle and in determining the vehicle accident potential for the calculation of premiums in automobile insurance.
Thus, in addition to an odometer which registers only the total miles driven, it would be desirable to provide means for permanently recording the "driving history" of the motor vehicle--more specifically, information about the number and types of trips traveled by the motor vehicle--during the life of the vehicle. As an example, the trips may be classified into different trip lengths; namely, trips of one mile or less; trips of one to two miles; two to three miles, etc. By separately counting the numbers of trips in each type or category (e.g., three mile trips), a "milage histogram" may be developed during the life of the vehicle. At the time of resale of this vehicle, this milage history would indicate to a prospective buyer the condition of the vehicle, thereby assisting both buyer and seller in determining an appropriate purchase price.
Other types of events for which statistics may be kept are numerous and varied. For example, in the case of a motor vehicle or an airplane, it may be desirable to accumulate statistics about the number of hours running time of the engine (event) at the different possible running speeds of the engine (type of event). For example, it may be desirable to know how many hours an engine was operated in the different speed ranges of 500-1000 RPM; 1000-1500 RPM; 1500-2000 RPM; . . . etc.
Statistics of this type are not limited to vehicles or engines, however. For example, it may be desirable to accumulate statistics about the use of electricity over a certain period of time (event) such as KWH/month during the period of the year or during the period that a total number of kilowatt hours are consumed. In this case, the KWH consumed for one month (event) may be classified into different "slices" of power consumed (type of event) such as 50-100 KWH/Mo.; 100-150 KWH/Mo.; 150-200 KWH/Mo . . . etc.
Still another example of an "event" involves the notes played by a musical instrument, such as a piano or organ, over the life of the instrument or even during the playing of a single musical composition. In addition to the total number of notes played, it would be desirable to know the relative frequencies with which the individual keys of the instrument are struck. Thus, the type of note (A, B, C, D . . . etc.) becomes the type of event.
In accumulating statistics of the above-mentioned kind, it would be desirable to store these data in a non-volatile memory in a substantially permanent manner so that the contents of the memory cannot be easily changed or tampered with. Thus, for example, the use of a conventional random access memory would permit the accumulated data to be readily changed so that the data could easily be falsified.